Electric controlling apparatus



Jan. 31, 1950 A. M. COHEN 2,496,120

ELECTRIC CONTROLLING APPARATUS Filed Sept. 19, 1945 2 Shets-Sheet 1 /4 llllllllllflllllllll llllllllllllllllllllllll llllllllllllllllllllllllllil lllillllllflll C) I "ll M ATTORNEY Jan; 31, 1950 A. M. COHEN I 2,496,120

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? I j J INVENTOR. v AFTAJ/F/ [0195 Patented Jan. 31, 1950 ELECTRIC CONTROLLING. APPARATUS Arthur M. Cohen, New Rochelle, N. Y., assignor toward Leonard Electric Company, a corporation of New York Application September 19, 1945, Serial'No. 617,256"

2 Claims.

This invention relates to electric controlling apparatus wherein a movable contact element variably engages a plurality of fixed contacts for the control of circuit connections. The invention is particularly applicable to rheostatic control for changing the connections of the resistive conductors but is also applicable where it is desirable to secure variable or segmental control by the movement of a controlling contact device. The invention also comprises improvements in the method of making the controlling means and the method of assemblingand forming the connections to the controlled device, such as a resistive device.

- In my former patent granted February 1, 1944,

No. 2,340,579, there is disclosed a variable contact device wherein a straight contact bar or roller is moved over a series of contacts arranged in general V form for securing variable control. The present invention comprises improvements thereon in the apparatus and in the method of making, together with improvements in the assem-' bling of and making connections to the controlled device.

The main object of the present invention is to simplify the structure and reduce the cost of materials and the labor required in assembling the parts. Further objects are to produce a form of apparatus that will have comparatively small size for obtaining the required results and 'be mechanically strong and durable over long continued use. Other objects and advantages will be'understood from the following description and accompanying drawings which illustrate a preferred embodiment of the: invention.

Fig. 1. is a plan view of the apparatus with the parts displacedand relatively positioned for clearness of explanation andshowing the variable contact device in connection with the controlled device; Fig. 2 is an enlarged edge view of one of the supporting elements for the fixed contacts; Fig. 3 is an enlarged inside view of the engaging faceof the element shown in Fig. 2; Fig. 4 is an; enlarged edge view of the other supporting elementior the fixed contacts; Fig. 5 is an enlarged inside view of the engaging face of the element; shown in Fig. 4; Fig. 6 is a view showing the method of assembling the parts and of formingthecontacts at the controllingdevice and forming the connections at the controlled device; and;

instance as a resistive device of the vform shown} 2 i in the Charles J. Ganci patent granted August 1, 1 944, No. 2,354,808, Fig. 5.

cated of plate form having a plurality of fixed connections or terminals l in a row extending from and respectively connected to the resistive conductors 2. These conductors are embedded in insulating material and covered by an insulatingcoating 3, shown partly broken away, and from which the conducting strips or terminals 1 outwardly extend. The leads 4 of the controlled circuit are connected tothe end strips l which places the resistive conductors 2 in series with each other in this circuit unless otherwise variably controlled.

A number of insulated wires 5' are respectively connected electrically at their lower ends to the strips 1 and extend to the variable controlling device. This is shown as having two parts 6 and l which areclamped together near their ends bythe screws 8. The clamping blocks or clamping elements 6 and I serve to hold between themthe ends of the insulated wires 5 in two rows 9 and I 0 at an obtuse angle to each other in the same sequential relationship as connected to the strips- II. The inclination of the rows is obtained by forming the inside faces of the blocks 6 and 1. inclined to each other to give the desired inclina-. tion to the rows of exposed ends of wires 5. In:

Fig. 1, for clearness, the wires 5 are shown passing to the underside of the supporting blocks. and then bent to have their ends extend up-' wardly between the blocks, but it will be under-.

stood that the variable contact device may be mounted in any desired relationship, to the con-. trolled device, such as over it, in which case the wires could pass directly up to and through the: blocks.

to engage the ends of the two inner wires, it:

will have no eliect on the controlled circuit because the inner wires are both connected to the inner strip l and all of the resistive conductors- Z-Wl1l be connected in series with each other in.

the controlled circuit. But when the bar is moved further downwardly it will bridge and succes-; sively short-circuit the connections to the resis- 7 Referring to Fig. 1 of the present case, the resistive device is indi-* The ends of the wires extend a short; distance above the blocks to form the rows 9 and. Ill which results in forming a series of exposed.

tive conductors until in its lowest position it will engage the ends of the two outside wires and thereby short-circuit all of the resistive conductors out of the controlled circuit.

In Fig. 1 only a few connecting wires and variable contacts are shown for clearness but any desired number may be used according to requirements. Also, instead of arranging the contacts in two rows at an obtuse angle to each other they may be otherwise related to secure the required sequential control of the contacts upon the movement of the movable element or device for obtaining any desired results, the formation of the clamping surfaces of the blocks readily determining the relative position of the contacts. The clamping blocks are preferably of moulded insulating material but when the spacing of the contacts is sufiicient to permit, the blocks may be of metal, the insulating coating on the wires then serving as sufficient protection. Also when the spacing between the wires and their permanency of position is sufficient to permit it, the wires need not be insulated in which case the clamping blocks necessarily would be of insulation. Also, although the use of connecting wires has been particularly referred to, the requirements may be such as to carry heavy currents in which case the connections may be flexible cables, strips, rods or bars.

As already stated, Fig. 1 shows comparatively few connections and variable contacts and refer ence is now made to Figs. 2 to 5 for showing the forms of the clamping blocks more fully and for adaptation to the utilization of a multiplicity of contacts and connections for securing refined control upon movement of the movable contact bar or contact element. Figs. 2 and 3 show the upper clamping block 6 of Fig. 1, having the holes [3 for receiving the clamping screws 8 of Fig. 1 and having a central hole M for receiving a central bolt or red for supporting the unit. On the inner face of this block and formed on the inclined surfaces are a series of grooves [5 adjacent to each other extending cross-wise to the block from one side to the other. Each of these grooves which may be of general wedge-shape is adapted to receive respectively one of the wires 5 of Fig. 1, thereby securing a multiplicity of contact surfaces at the ends of the wires, the wires in turn being connected to a corresponding multiplicity of connecting strips I. This improvement is thus well adapted for securing a considerable variation in contacts engaged upon comparatively small movement of the contact bar. It thereby is capable of refined and graduated control between steps of resistance upon movement of the contact bar. Extending cross-wise to the grooves i5 are shown a pair of longitudinally extending grooves 15 on each of the inclined surfaces. These grooves are preferably wedgeshaped and are deeper than the grooves [5, as shown by the dotted line IS in Fig. 2.

Figs. 4 and 5 show the lower clamping block I of Fig. 1, having the holes I3 for the fastening screws 8 and the hole M for the main support. A pair oi longitudinally extending projections I! are formed on each inclined surface of this lower block corresponding in position to the grooves I6 of the upper block. These projections are preferably of wedge-shape with a rounded front edge. They are for the purpose of firmly and securely holding the wires 5 in place between the blocks. Thus after the wires are assembled in place in the grooves [5 of the block 6, the block I is placed over them causing the projections IT to engage the wires and bend them more or less into the grooves [5. These indentations in the wires prevent their displacement. After the wires are clamped and held in place, their projecting end portions are cut off to form ends projecting a short distance beyond the blocks. The faces of these ends are then ground and polished ofi to form them in even alignment, the ends of the wires, or ends of their wire cores, forming the exposed contact surfaces engaged by the movable contact.

A very advantageous method of assembling and connecting the wires 5 greatly facilitates this process in the reduction of time required and in the avoidance of mistakes in connections because itis a continuous sequential operation with a continuous wire. It also avoids the necessity of connecting and handling a multiplicity of short wires. Fig. 6 and 7 show the method. Only a. few of the wires 5 are shown for simplicity. The resistive device 18 of Fig. 1 is shown partly broken away in Fig. 6 and from this the connecting strips I extend upwardly. These strips are usually ofcopper and for the purpose of this invention are each provided with an integral projection extending from one edge of each strip. This projection is in the form of an outer portion I9 connected to the strip by a small neck portion |9a extending from the middle of the portion IS. A part of the block 6 having the grooves for receiving the wires is shown in Fig.6.

The method of assembling the continuous wire will be explained by starting at the right-hand strip I. From one end 20 of the wire it is passed down in front of the neck-19a of the first strip,

then under the neck to and through a groovel5 of the block 6. Beyond the groove the wire is bent and returned through the next groove tothe left from which it passes to the back of the, next left-hand strip l and then under and up in front of its neck I911. The wire is then bent and passed down in front of the neck of the next left-hand strip and then from the back of this strip the wire is passed to and through the next left-hand unoccupied groove l5. It is then bent and passed back through the next left-hand groove to the next left-hand strip I and so on, as" already described, to complete winding of the wire to all of the strips l and in all of the grooves.

The individual wires in the block 6 after being clamped in place by the block 1 are then formed by cutting off the loops at one side of the block and a little beyond it, as indicated along the dot and dash line 2|. The exposed ends are afterwards ground and polished to form the exposed contact surfaces as already described. The individual connections of the wires to the strips i are formed by first bending the projections 19 over the wires, as indicated by dotted lines in' Fig. 7 and then the short loops 24 extending between and above the strips are cut off close to the top of the strips, as indicated along the dot and dash line 22. This forms a mechanical con-- nection of the individual wires 5 to the strips or posts I but not an electrical connection because insulated wire is assumed to be used in this instance. However, the metal core of each wire isexposed at its cut-01f end at the top of each strip;'- and the electrical connection is made by solder-' ing this exposed end to the top of the strip, as; by adding a small drop of solder 23 to the exposed top portions as shown in Fig. 7.

The foregoing method of assembling the con ductors and of forming the electrical connections 76 is easily and quickly accomplished and substan tially eliminates errors or mistakes in the forming the sequence of connections.

Although a particular disclosure of the invention as regards apparatus and method of making has been made, it will be understood that various modifications thereof may be made for adaptation to particular requirements without departing from the scope thereof.

I claim:

1. Electric controlling apparatus comprising a plurality of conductors having their ends exposed to form contact surfaces and positioned to form two rows of contact surfaces at an angle to each other converging toward an apex, a contact bar movable over said surfaces in a direction to correspondingly bridge said two rows, and clamping elements on opposite sides of said conductors for holding said conductors between them and having their opposed faces inclined in the direction of said rows for positioning said conductors.

2. Electric controlling apparatus comprising a plurality of conductors in the form of wires having their ends exposed to form contact surfaces and positioned to form two rows 0f contact surfaces at an angle to each other converging toward an apex, a contact bar movable over said surfaces in a direction to correspondingly bridge said two rows, and clamping elements on opposite sides of said conductors for holding said conductors between them and having their opposed faces inclined in the direction of said rows for positioning said conductors.

ARTHUR M. COHEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

